# Santa Clara, CA — Drinking Water Quality (2024)

> Contaminant levels for the Santa Clara, CA public water system from its 2024 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/santa-clara/2024
- JSON API: https://www.thewatermap.com/api/water/ca/santa-clara/2024
- Source: the utility's annual Consumer Confidence Report (CCR)
- Verification: transcribed by a model, cross-checked by a second model, approved before publishing
- Reporting year: 2024
- Contaminants measured: 18
- Contaminants with a federal limit: 16
- Contaminants at or above the federal limit: 0
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Chlorine | Disinfectants | 0.8 mg/L (Average) | System-wide | 4 mg/L (MCL) | Within the limit |
| HAA5 | Disinfection byproducts | 34.9 ug/L (Average) | System-wide | 60 ug/L (MCL) | Within the limit |
| Perchlorate | Disinfection byproducts | Not detected ug/L (Average) | Valley Water | 6 ug/L (MCL) | Within the limit |
| TTHM | Disinfection byproducts | 56 ug/L (Average) | System-wide | 80 ug/L (MCL) | Within the limit |
| Fluoride | Inorganic chemicals | 0.7 mg/L (Average) | Valley Water | 2 mg/L (MCL) | Within the limit |
| Nitrate | Inorganic chemicals | 3.3 mg/L (Average) | CSC Well Water | 10 mg/L (MCL) | Within the limit |
| Arsenic | Metals | Not detected ug/L (Average) | SFPUC | 10 ug/L (MCL) | Within the limit |
| Barium | Metals | 0.14 mg/L (Average) | CSC Well Water | 1 mg/L (MCL) | Within the limit |
| Chromium, Hexavalent | Metals | 1.9 ug/L (Average) | CSC Well Water | 10 ug/L (MCL) | Within the limit |
| Copper | Metals | 0 mg/L (Average) | System-wide | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | 1 ug/L (Average) | System-wide | 15 ug/L (Action level) | Within the limit |
| Lithium | Metals | Not detected ug/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Escherichia coli (E. coli) | Microbial | 0 (Average) | System-wide | 0 (MCL) | None detected |
| Giardia lamblia | Microbial | 0.02 (Average) | Valley Water | No federal limit | Detected — no federal limit |
| Total Coliform | Microbial | Not detected % (Average) | System-wide | 5 % (MCL) | Within the limit |
| Gross Alpha | Radionuclides | 3.3 pCi/L (Average) | SFPUC | 15 pCi/L (MCL) | Within the limit |
| Uranium | Radionuclides | 1.3 pCi/L (Average) | SFPUC | 20 pCi/L (MCL) | Within the limit |
| Toluene | VOCs & pesticides | 0.6 ug/L (Average) | CSC Well Water | 150 ug/L (MCL) | Within the limit |

## What these contaminants are

- **Chlorine** — A disinfectant added to drinking water to kill bacteria and viruses. Effective and necessary, but high residual levels can cause taste and odor issues; the EPA caps the residual disinfectant level.
- **HAA5** — Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. Long-term exposure above the federal limit is associated with an increased cancer risk.
- **Perchlorate** — A chemical used in rocket fuel and fireworks that can also form during disinfection. Can interfere with thyroid hormone production; has no national enforceable limit but is regulated in some states.
- **TTHM** — Total trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
- **Fluoride** — A mineral often added to drinking water to help prevent tooth decay. Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
- **Nitrate** — A compound from fertilizer runoff, septic systems, and erosion of natural deposits. Levels above the federal limit can cause 'blue baby syndrome,' a serious oxygen-transport condition in infants.
- **Arsenic** — A naturally occurring element that also enters water from industry and agriculture. A known human carcinogen; long-term exposure is linked to skin, bladder, and lung cancer.
- **Barium** — A metal from erosion of natural deposits and industrial discharge. Long-term exposure above the federal limit can raise blood pressure.
- **Chromium, Hexavalent** — Hexavalent chromium ('chromium-6') — the more toxic form of chromium. A known carcinogen by inhalation; regulated nationally only within the total-chromium limit, with stricter limits in some states.
- **Copper** — A metal that enters water from corroding household plumbing. Short-term exposure causes stomach distress; long-term exposure can damage the liver and kidneys.
- **Lead** — A toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. There is no safe level of lead; it harms brain development in children and raises blood pressure in adults. The EPA sets an action level, not a health goal above zero.
- **Lithium** — A naturally occurring element found in some groundwater. No enforceable federal limit; on the EPA contaminant candidate list for further study.
- **Escherichia coli (E. coli)** — Escherichia coli — bacteria found in the gut of humans and animals. Its presence in drinking water indicates fecal contamination and a real risk of waterborne illness.
- **Total Coliform** — A group of bacteria used as an indicator of overall water-system sanitation. Coliforms themselves are usually harmless, but their presence signals that disease-causing organisms could enter the system.
- **Gross Alpha** — Gross alpha particle activity — a combined measure of alpha-emitting radioactive substances. Long-term exposure above the federal limit increases cancer risk.
- **Uranium** — A naturally occurring radioactive metal from erosion of natural deposits. Long-term exposure above the federal limit can damage the kidneys and increase cancer risk.

## How to read this

- A water-quality report covers an entire service area, not a single address.
- 'Federal limit' is the EPA standard (MCL, action level, treatment technique, etc.) that the measured level is compared against.
- 'At or above the federal limit' means the utility's own reported figure met or exceeded that standard.

_Figures are the utility's own published numbers. Generated 2026-05-25 from thewatermap.com._